Hello list!
I have a newly required TR-7, S/N 3857 with remote VFO and PS S/N 5479. I will no doubt have some questions as I go forward with its restoration repair. Are there any documents that compile or list the "must do" vs. "should do" vs. "very nice to do" upgrades/changes and modifications for the TR-7? Or should I just try to search all the posts for the info, like newer board versions etc.? I know there are a lot of very capable people on here that have done all this already so I do not want to try to "re-invent the wheel". RE: TANTALUM CAPs I also have 3- Racal 6790GMs. They are literally loaded with tantalums with few electrolytics on the boards other than the PS. I have had some tantalums explode also leaving a black/dark gray deposit on everything around them. It stains and is hard to clean!! What I have found is that if you observe a small dark spot that appears to penetrate the outer shell and resembles a small volcano crater no larger than a pin point or a little larger, CHANGE THE CAP. IF IT HAS THE BLACK SPOT AND HASN'T YET FAILED IN THE EXPLOSIVE MODE OR HASN'T ALREADY FAILED DOSSIALY INTACT, IT WILL FAIL! I have changed out over a 100 tantalums in these radios so far. To change one or not is a personal call but the cleanup after one pops is a PITA. It can also damage components ahead of it if it shorts to ground and the supply is stiff enough. At least look them over closely for the spots. They don't always have the spots but many times they will have them at some time before failure. Of course the lack of spots doesn't mean they won't fail but a spot is a sure sign of impending failure at some point. Thanks in advance for any suggestions you folks have for the TR-7. 73, Walt KR4HV kr...@numail.org
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